Prior object-knowledge sharpens properties of early visual feature-detectors.


Type
Article
Change log
Authors
Dakin, Steven C 
Fletcher, Paul C 
Abstract

Early stages of visual processing are carried out by neural circuits activated by simple and specific features, such as the orientation of an edge. A fundamental question in human vision is how the brain organises such intrinsically local information into meaningful properties of objects. Classic models of visual processing emphasise a one-directional flow of information from early feature-detectors to higher-level information-processing. By contrast to this view, and in line with predictive-coding models of perception, here, we provide evidence from human vision that high-level object representations dynamically interact with the earliest stages of cortical visual processing. In two experiments, we used ambiguous stimuli that, depending on the observer's prior object-knowledge, can be perceived as either coherent objects or as a collection of meaningless patches. By manipulating object knowledge we were able to determine its impact on processing of low-level features while keeping sensory stimulation identical. Both studies demonstrate that perception of local features is facilitated in a manner consistent with an observer's high-level object representation (i.e., with no effect on object-inconsistent features). Our results cannot be ascribed to attentional influences. Rather, they suggest that high-level object representations interact with and sharpen early feature-detectors, optimising their performance for the current perceptual context.

Description
Keywords
Adolescent, Adult, Attention, Female, Humans, Male, Orientation, Photic Stimulation, Visual Cortex, Visual Perception, Young Adult
Journal Title
Sci Rep
Conference Name
Journal ISSN
2045-2322
2045-2322
Volume Title
8
Publisher
Springer Science and Business Media LLC
Sponsorship
Wellcome Trust (095692/Z/11/Z)
Wellcome Trust (206368/Z/17/Z)
Wellcome Trust